Medical dressing for application and maintenance of medication on body tissue

ABSTRACT

A medical method and dressing for application and maintenance of medication on healthy, damaged diseased or infected living tissue. Medication is applied to body tissue and then coated with a bioadhesive providing medication maintenance on tissue and protection from body and other liquids or abrasion thereby preventing removal of the medication during a healing or treatment process.

This application is a divisional of application Ser. No. 08/556,570filed Nov. 30, 1995, now U.S. Pat. No. 5,762,955, which is acontinuation of Ser. No. 08/191,162, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to applying a medication tohealthy, damaged, diseased, or infected living tissue and coating themedication with a bioadhesive as a method of maintaining the medicationand protecting tissue during a healing and medicating process.

2. Description of the Prior Art

It is well known that many types of medication may be applied tohealthy, damaged, diseased, or infected living tissue to assist ahealing process, prevent additional harm and infection, and relieve painor suffering. This has been accomplished by a variety of methods.Depending upon the physiological problem and the type of medication,medication may be injected into the blood stream, taken orally,transferred into the body through healthy tissue or applied directly tothe damaged, diseased or infected tissue. In clinical practice there areproblems when applying medication directly to healthy, damaged, infectedor diseased tissue.

After applying the medication to the tissue area, there is a medicalneed to maintain the presence of the medication during the healingprocess, to prevent foreign matter from entering or affecting thetissue, and to protect the injured area from mechanical interference.Presently this need is accomplished by a number of methods such asbandages, physical restraints, and continual maintenance by cleaning,medication administration and re-bandaging. All these devices andtechniques may cause discomfort, expense, time, and may result ininefficient healing.

There is also a medical need to apply and maintain medication on healthytissue for absorption into the body. This type of application involvesusing a medical device for transdermal delivery (U.S. Pat. No.4,645,502) or fabric backed dressings that also need maintenance andreplacement.

Bioadhesives have been used in surgical methods, dental methods, tissuebonding and applying bandages. U.S. Pat. No. 3,223,083 was an earlydisclosure of a method for securing bones and skin using bioadhesives.The bioadhesives have also been used to bond bandages, sutures, (U.S.Pat. No. 5,254,132) porous materials (U.S. Pat. No. 4,906,240) orflexible materials (U.S. Pat. No. 4,900,303) to tissues for medicalpurposes. These bioadhesive techniques involve adhesion of healthytissue to cellular, plastic, porous, or fabric materials that protect,dispense medication, or sutures closing damaged or diseased tissue.However, the use of these bioadhesives employing auxiliary devices mayinterfere with the healing process and make clinical processes moredifficult.

In actual clinical situations the above techniques and methods may becomplex or simply ineffective. Such clinical situations may relate toareas of the body where reliable, simple, predictable, effectiveretention of medication is extremely difficult or impossible, i.e. wettissues, limited access, restricted visibility and lighting, mechanicalinterference (occlusion of teeth -orally, areas of excessive mobility,etc.)

In oral applications, liquids and mechanical interference by tongue,teeth, and cheeks retard the healing process. Saliva may dilute or washaway the medication. Currently, a dental paste mixed withhydrocortisone, called Orabase® by Colgate-Hoyt/Gel-Kam requiresapplication after each meal. A similar dental paste, Kenalog® byWestwood Squibb, needs re-application every 12 hours.

There are many other anatomical regions where internal or externalfluids may interfere with the application and retention of medication oninjured tissue.

The present invention has solved the problems described above that arecommon in medical and dental practice.

SUMMARY OF THE INVENTION

The present invention relates to applying a medication to healthy,damaged, diseased, or infected tissue including burns, wounds,pathological lesions, pre-cancerous infections, dermatitis, and surgicalincisions and then coating a bioadhesive over the medication. Thebioadhesive coating maintains the presence of the medication on theinjured tissue, seals the injury, and protects the medication and tissuefrom possible contamination, dilution, and mechanical interference thatmay cause additional tissue injury. The adhesive coating provides ameans to maintain the medication throughout the healing process ofdamaged, infected or diseased tissue. The bioadhesives may be appliedover various medications such as in intra-oral environments where bodyfluids or areas of excessive mobility easily removes topical medication,rendering medication ineffective. Other body regions where fluids mayremove medication include intra-abdominal, intra-anal, and other regionswhere circumstances make adhesion of medication difficult or impossible.

The bioadhesive may be coated over medication that has been applied toall internal and external parts of a tissue wound or gash prior toclosing the wound. The wound is then pressure closed, sealing the woundand medication on the injured tissue. If the medication is applied tohealthy tissue for transdermal delivery, the bioadhesive applied overthis medication maintains the medication on the tissue throughout thedelivery process in an identical manner as on injured tissue.

Application of the bioadhesive on the medication may be accomplished bywiping using sterile gloves, applying with appropriate devices, spray,painting, or other means to produce a continuous adhesive film on themedicated tissue.

If additional support for damaged, diseased, or infected body sectionsis required, bandages, splints, other medication dispensing devices,prosthetic devices or any other devices may be applied in conjunctionwith the inventive process.

For some applications, selected medication may be combined with theproper adhesives prior to application to provide a single step processwhere conditions and tissue locations make the two step applicationprocess difficult.

Accordingly, the object of the invention is to provide a method formaintaining medication on damaged, diseased or infected tissue duringthe healing process.

Another object of the invention is to provide clinical practitionerswhen working in clinical situations with a means of using a reliable,simple, predictable, and effective method for retention of medication ondamaged, diseased, or infected tissue.

Another object of the invention is to provide a method for maintaining acontinuous medication presence on tissue exposed to fluids during thehealing process.

Another object of the invention is to provide a method for maintainingcontinuous medication on healthy tissue for transdermal delivery.

Another object of the invention is to provide a method for maintainingcontinuous medication on tissue in combination with prosthetic devices,sutures, or mechanical devices used to attach severed digits or limbs,such avulsed teeth, eyeballs, or toenails.

Another object of the invention is to provide a method for applying acombination mixture of a bioadhesive and a medication on or inanatomical regions where access makes the application of separatemedication and bioadhesive difficult.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows sectional view of a topical tissue coating.

FIG. 2 shows a sectional view of a deep wound with the biologicalmedication and adhesive coating.

FIG. 3 shows the closure of the FIG. 2 wound and additional topicaldressing.

FIG. 4 shows the application of a combination of medication andbioadhesive mixture on injured tissue.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to the treatment of healthy, damaged,diseased, or infected biological tissue by applying a bioadhesivecoating in conjunction with a medication. External biological bodytissue may be affected by many harmful afflictions including but notlimited to various bruises, burns, dermatologic afflictions, infections,gashes, wounds, herpes sores, canker sores, or intra-oral lesions andskin cancers, such as leukoplakia. Internal body tissues may also beaffected by diseases, infections, and injuries and thus requirebiological medication. For example, intra- abdominal, intra-anal, andintra-oral, intra-vascular, intra-ocular and any other regions wherecircumstances require application of medication.

FIG. 1 indicates the process for treatment of surface afflictions. Theafflicted tissue and surrounding area is thoroughly cleaned anddisinfected using normally accepted methods including but not limited toanti-bacterial soaps. Medication 11 is applied to the injured oraffected surface 12 by normal methods including swabbing, flowing,spraying, wiping or use of special applicators. Sufficient quantity isapplied to promote a healing process of the injured or diseased tissue.

Next, the bioadhesive liquid 13 is applied to the surface of themedication for retention and protection purposes. Bioadhesiveapplications are readily accomplished by normal methods includingswabbing, flowing, spraying, wiping or use of special applicators. Thequantity of bioadhesive should be sufficient to provide a cover to themedication and thereby seal the surface while attaching to the tissue.The bioadhesive polymerizes and bonds to tissue to form a protective andresilient layer on the medication. The resulting product of the processis a tissue dressing that protects the afflicted tissue and maintainsmediation on the tissue during the healing process. The application ofmedication and bioadhesive on healthy tissue for transdermal medicationdelivery is identical to the method shown in FIG. 1.

FIG. 2 shows a deep flesh wound receiving the inventive treatmentmethod. The medication 11 is applied internally to all surfaces of theexposed flesh 12 after cleaning and disinfecting all areas. Thebioadhesive 13 is then applied to all outer surfaces of the medication,followed by forceful closure of the wound. The closure is physicallymaintained until the bioadhesive reacts, bonding the internal surfacestogether, thereby encapsulating the medication next to the injuredsurfaces. This bonding time will take less than twenty minutes. Thisclosed wound is depicted in FIG. 3. This same procedure applies to thereattachment of severed body parts such as avulsed teeth, toenails,eyeballs, or severed digits or limbs.

FIG. 3 also indicates an auxiliary exterior bandage, dressing, precastfilm 14 or sutures that may be used over the inventive method ifrequired for additional external protection.

FIG. 4 indicates a method of combining the medication 15 with thebioadhesive 16 prior to applying on cleaned and disinfected livingtissue or such as a vertical side 18 of an open wound 20 in inaccessibleareas of a body where the individual component applications are notpractical. This method combines a medication with a bioadhesive in a 0.1to 50 weight percent medication of total combination weight. The weightpercent depends upon the type of injury, medication and bioadhesives.

The medications used in the inventive method are not critical to thisinvention and as used herein is meant in the broadest sense as amaterial that is intended to produce some beneficial effect on theapplied tissue or organism. These include but are not limited tocorticosteriods, fluorouracil, obtundants, anesthetics, antibiotics,fungicides, anti-inflammatory agents, antibacterial agents, antisepticagent, and any other medication or combination of medicines used in theprocess of healing injured or infected tissue, promoting blood clottingor preventing blood clotting, destroying cancer cells, palliativetreatments and killing of bacteria or viruses.

Bioadhesives are chemical compounds that have a property or ability tobond to body tissue. There are several kinds of bioadhesives suitablefor the invention and the selection depends upon the location of thetissue and the type of medication selected for treating the injury orinfection. The bioadhesive chemical groups most useful belong to thecyanoacrylate adhesives, polyurethanes and polypeptide chain adhesivesthat may be used on wet surfaces. For some cases, the silicones,polyacrylamides, polyisobutylene-mineral oil adhesives, tackified EVAcontact adhesives, tackified styrene-isoprene-styrene block copolymers(SIS) may be suitable. For most applications, the bioadhesive shouldhave the property of being biodegradable. Cyanoacrylate adhesivessuitable for coating medications include but are not limited to thegroups:

where R is an alkyl or other compound. The R substitute is alkyl of from10 or 12 or more carbon atoms and preferably n-butyl (—CH₂—CH₂—CH₂—CH₃).R′ is an individual hydrogen or methyl. These cyanoacrylates aredescribed in U.S. Pat. No. 4,650,826; 4,035,334; 3,995,641; 3,667,472;3,551,676; and 3,527,224 all of which are incorporated herein in theirentirety by reference. Upon application to tissue, the cyanoacrylatecompound will polymerize to encapsulate the medication and bond to thetissue. Preferably, thicker viscosity and fast reacting monomers of thecyanoacrylate are desirable.

The polypeptides, described in U.S. Pat. No. 5,197,973, consist ofpeptide sequences that are capable of forming a-helices in solution.

The urethane adhesives, described in U.S. Pat. No. 5,173,301; 4,994,542;4,806,614; and 4,740,534, contain at least one NCO terminatedhydrophilic urethane prepolymer.

The adhesive selected for the invention should retain the medication inthe afflicted area for a period of one to twenty days while healingoccurs.

Biological tissues discussed in the invention include human, animal, andvegetable species.

The following example illustrates only some of the many possible uses ofthe invention and are not intended to limit the scope of the claims inany manner.

EXAMPLE

The present invention was subjected to final clinical test in the mostdifficult of clinical situations and most primitive conditions in thejungles of Guatemala by treating the Kekchi Indians. Numerousmedications were applied and retained by a butyl cyanoacrylate typebioadhesive on large wounds, infections, and lesions, both extra-orallyand intra-orally after cleaning and disinfecting the afflicted tissueand surrounding areas. No additional treatment was required for ten daysfor the lesions and seven to ten days for oral treatments. These weresurprising and unexpected long term results necessitated by difficultconditions and numerous patients having little or no access to medicaltreatment. After thirty days there were no apparent complications orsequelae. All treatments were proven successful.

From the above description of the invention, various changes andmodifications in the methods will occur to those skilled in the art. Allsuch modifications coming within the scope of the appended claims areintended to be included therein:

What I claim:
 1. A medical dressing in liquid or gel form, the medicaldressing being for application against a section of living tissue andbeing adapted for being shaped in-situ to conform with the section ofliving tissue being covered with the dressing, the medical dressingcomprising: a cyanoacrylate adhesive in a liquid or gel state; and amedication, the medication being intermixed within the cyanoacrylateadhesive in a ratio of from approximately 0.1 to approximately 50percent weight of medication weight to total weight of cyanoacrylateadhesive to create a cyanoacrylate adhesive and medication mixture, sothat application and in situ curing of the cyanoacrylate adhesive andmedication mixture over the living tissue creates a dressing that hasassumed the shape of the living tissue covered by the dressing.
 2. Adressing according to claim 1 wherein the cyanoacrylate adhesive is ofthe group:

wherein R is another compound containing carbon.
 3. A dressing accordingto claim 2 wherein alkyl is n-octal R is an n-octyl alkyl.
 4. A dressingaccording to claim 1 wherein the cyanoacrylate adhesive is of the group:

wherein R is an alkyl of from 1 to 12 carbon atoms and R′ is anindividual hydrogen or methyl.
 5. A dressing according to claim 1wherein said cyanoacrylate adhesive and medication mixture is of a tackyconsistency, so that the cyanoacrylate adhesive and medication mixtureclings to the living tissue on application of the medication mixture onto a vertical side of an open wound.
 6. A mixture in liquid or gel fromfor creating an in situ medical dressing, the medical dressing beingagainst a section of living tissue, the mixture comprising: acyanoacrylate adhesive in a liquid or gel state; and a medication, themedication being intermixed within the cyanoacrylate adhesive in a ratioof from approximately 0.1 to approximately 50 percent weight ofmedication weight to total weight of cyanoacrylate adhesive to create acyanoacrylate adhesive and medication mixture, so that application andcuring of the cyanoacrylate adhesive and medication mixture on thesection of living tissue creates a dressing that has assumed the shapeof the living tissue covered by the cyanoacrylate adhesive andmedication mixture.
 7. A dressing according to claim 6 wherein thecyanoacrylate adhesive is of the group:

wherein R is a compound containing carbon.
 8. A dressing according toclaim 7 wherein R is an alkyl of from 1 to 12 carbon atoms.
 9. Adressing according to claim 6 wherein the cyanoacrylate adhesive is ofthe group:

wherein R is an alkyl of from 1 to 12 carbon atoms and R′ is andindividual hydrogen or methyl.
 10. A dressing according to claim 6wherein said cyanoacrylate adhesive and medication mixture is of a tackyconsistency, so that the cyanoacrylate adhesive and medication mixtureclings to the living tissue on application of the medication mixture onto a vertical side of an open wound.